Show Media Router toolbar icon ephemerally for MR dialogs

chrome/browser/ui/toolbar/mock_media_router_action_controller.cc

Index: chrome/browser/ui/toolbar/mock_media_router_action_controller.cc
diff --git a/chrome/browser/ui/toolbar/mock_media_router_action_controller.cc b/chrome/browser/ui/toolbar/mock_media_router_action_controller.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5a6e4ee534b7ab3fd382a42e87eaca5febcc3d95
--- /dev/null
+++ b/chrome/browser/ui/toolbar/mock_media_router_action_controller.cc
@@ -0,0 +1,16 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/ui/toolbar/mock_media_router_action_controller.h"
+
+#include "chrome/browser/media/router/media_router_factory.h"
+
+MockMediaRouterActionController::MockMediaRouterActionController(
+    Profile* profile)
+    : MediaRouterActionController(
+          profile,
+          media_router::MediaRouterFactory::GetApiForBrowserContext(profile),
+          nullptr,
+          nullptr) {}
+MockMediaRouterActionController::~MockMediaRouterActionController() {}